This paper presents a stochastic adaptive control algorithm which is shown to possess the following properties when applied to a possibly unstable, inverse stable, linear stochastic system with unknown parameters, whenever that system satisfies a certain positive real condition on its (moving average) noise dynamics. 1) The adaptive control part of the algorithm stabilizes and asymptotically optim...
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The optimal input design problem is considered for discriminating autoregressive models when the output variance is constrained. It is shown that aDs-optimal input design can be achieved with an input comprised of a finite number of sinusoidal components with frequencies and amplitudes determined by solving a system of nonlinear equations. Digital simulation studies illustrate the usefu...
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The aim of this note is to apply an algebraic test such as the Hurwitz or the Routh, or the Hermite method to a certain class of distributed parameter systems with a distributed lag. A characteristic equation of such a system is truncated according to Rouché's theorem to determine a range of adjustable parameterKfor which the truncated system and the system with a distributed lag a...
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A condition proven in the above paper to be a necessary condition for Hurwitz polynomials is not new. It is part of a necessary and sufficient condition for a polynomial to be Hurwitz.
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Two examples are given to indicate that in 2-D coefficient assignment (model matching) some cancellations are unavoidable (in the author's belief) and the "split" condition (not only the zero coprimeness) is necessary.
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This correspondence is concerned with the steady-state behavior of autonomous systems of any order containing nonlinear elements which lie within the Hurwitz sector for large input magnitudes and outside it for small inputs. It provides an alternative viewpoint to that given in the above paper for second-order systems.
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It is shown that the closed-loop poles of the continuous-time Kalman filter reside in a region in the left half of the complex plane that is confined by two concentric circles whose radii depend on the system matrices and the signal-to-noise ratio. This region includes the system open-loop poles and excludes the imaginary axis. In the case where the system dynamic matrix has a simple eigenstructur...
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A new nonparametric estimate for nonlinear discrete-time dynamic systems is considered. The new algorithm is weakly consistent under a specific condition on the transition probability operator of a stationary Markov process. The estimate is applicable when a parametric state model of the system is difficult to choose.
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The idea of advanced controller design using modern state estimation, identification, and control techniques with a nonlinear system inverse for robot arm applications is presented. A generalized solution for the trajectory regulator of the robot arm controller using the inverse system is given.
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A recursive instrumental variable algorithm is derived for the overdetermined case in which the number of instruments is greater than the number of estimated parameters. In some applications, the algorithm provides improved parameter estimation accuracy, compared to the standard recursive instrumental variable method. The performance of the algorithm is illustrated by simulation results.
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An electromyographic (EMG) signal pattern recognition system is constructed for real-time control of a prosthetic arm through precise identification of motion and speed command. A probabilistic model of the EMG patterns is first formulated in the feature space of integral absolute value (IAV) to describe the relation between a command, represented by motion and speed variables, and location and sh...
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Two regions are found inside the complex unit circle that exclude all the poles of the discrete stationary Kalman filter. The sizes of these regions depend on the ratio between the intensities of the signal and the measurement noise, and in the limit where this ratio tends to infinity, one of the regions shrinks to the origin.
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The reduced-order representation of possibly nonstationary observations of Markovian processes with additive measurement noise is considered. A canonical variable model reduction scheme is derived in a geometric setting.
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This paper is concerned with the property of stabilizing a nonlinear system to a specified equilibrium point arbitrarily fast by appropriate smooth feedback. Two closely related forms of this property are explored. One refers to the asymptotic transfer to the critical point with exponential decay, and it is shown that the systems possessing the above property are precisely those whose correspondin...
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In this note, we present two worked examples of disturbance decoupling for nonlinear systems, using the concept of controlled invariance, which was recently generalized to nonlinear systems. In the first example, we explicitly construct a feedback which decouples a disturbance from the vertical components of the axes of a rotating rigid body, while the second example deals with a particle in a pot...
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This paper considers the general regulator problem with internal stability where the measured outputs are not necessarily the same as the regulated outputs. Using polynomial matrix techniques, necessary and sufficient conditions are obtained in terms of skew-primeness of two polynomial matrices; one of these polynomial matrices represents the disturbance modes, whereas the other is the polynomial ...
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This note presents an algorithm to carry out the division of two polynomial matrices and an algorithm to transform a polynomial matrix into a row-reduced one. These algorithms are useful in the polynomial matrix fraction description of multivariable systems.
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Aims & Scope

In the IEEE Transactions on Automatic Control, the IEEE Control Systems Society publishes high-quality papers on the theory, design, and applications of control engineering. Two types of contributions are regularly considered